Question

What mass of calcium metal contains the same number of atoms as 12.16 g of magnesium

Answer 1

Answer:

20.268 grams of calcium metal contains the same number of atoms as 12.16 g of magnesium.

Explanation:

Atomic mass of magnesium= 24 g/mol

Mass of magnesium given = 12.16 g

Moles of magnesium= $\frac{12.16 g}{24 g/mol}=0.5067 mol$

1 mol = $N_A=6.022\times 10^{23}$ atoms/ molecules, ions

Number of atoms of magnesium in 0.5067 moles of magnesium:

$0.5067 \times 6.022\times 10^{23}=3.051\times 10^{23} atoms$

Calcium metal contains the same number of atoms:

Moles of calcium = n

$3.051\times 10^{23} atoms=n\times 6.022\times 10^{23}$

n = 0.5067 mol

Atomic mass of calcium = 40 g/mol

Mass of 0.5067 moles of calcium:

0.5067 mol × 40 g/mol = 20.268 g

Answer 2

For the answer to the question above, 20.05 g Ca is around 12.16 g Mg. 
Since 24.31 g Mg is about twice 12.16 g Mg, then the amount of Ca would double as well, so it would be about 40.1 g Ca. I hope this helps